Yep, otherwise, don't think things may go well

Analysis is crucial in any venture. No matter how lucrative it is.
Right, if it's with mining. There's really a lot of changes that can happen on every cycle. Like what we are in today, if it is profitable for the early ones that have done that then it is. But expect that there will be changes, from difficulty to other matters that would affect its profitability soon. Well, I guess that there are some folks out there that would like to mine afterwards when they're done taking profits from the market on this bull run. If that is so, I think that it's a good idea so that your money will keep on making new ones.